It is well known that the box-like shape of truck storage areas, and the trailer sections of a tractor-trailer combination, results from the need or desire to optimize cargo space. It is also well known that this boxlike configuration is not aerodynamically efficient and that the aerodynamic drag resulting from the box shape accounts for a considerable percentage of the fuel consumption of large trucks and tractor-trailer combinations during higher speed applications, such as on a highway. In an effort to improve the operating efficiency of such vehicles, the tops of the cabs of trucks and tractors and the upper forward ends of trailers have been provided with a wide variety of wind-foil or other wind fairing devices.
For the same purposes, numerous suggestions have been made to modify the rear ends of trucks and trailers in order to provide them with a variety of streamlining and/or drag reducing devices. However, while the devices fitted to the front of the truck and/or trailers can be rigid and permanent in character (in that the areas on which the air foils are mounted do not need to be accessed in connection with use or operation of the vehicle), the rear ends of trucks and trailers typically must be accessible in that the doors to close the rear end of the truck or trailer are located therein. These doors are typically large in nature, and cover most of the rear end of the truck or trailer since they provide access to the cargo area of the truck or trailer, and are used for loading and unloading purposes.
Accordingly, streamlining and drag reducing devices designed for use on the rear ends of trucks and trailers either have to be detachable or designed so that they can be temporarily removed, or moved to a position wherein access to the truck or trailer interior is possible.
However, in the prior art devices, removal and storage of the streamlining devices is typically a time-consuming operation. Also, removal of the devices also requires storage space on the truck if the operator wishes to keep possession of the device in the situation where a trailer is left at a location. Further, permanent mounting of the device on the truck or trailer doors undesirably exposes the device to adverse weather and other conditions during times of non-use of the device. The exposed device is also subject to other potential damage, such as acts of vandalism, or the like. It will be easily appreciated that such exposure and potential damage shortens the life of the device.
For example, in U.S. Pat. No. 5,058,945, a long-haul vehicle streamlining apparatus is provided which has an attachment belt fitted around the outside of the trailer. The belt is drawn tight to the trailer by a series of hooks and straps, and a roughly cone-shaped streamlining device is connected to the belt. The streamlining device has a series of supporting battens or support rods, and is held together in the middle of the device by a strap. For loading or unloading, the streamlining device is separated to provide access to the trailer doors.
While this device provides some improvement over prior art devices, it requires a series of belts and gaskets to seal to the trailer, and can be difficult to use when access to the interior of the truck or trailer is desired. For example, belts must be removed to divide the cone-shaped device, and the separated fabric portions must be draped out of the way in order to access the trailer interior.
Alternatively, the entire device can be removed from the trailer by removal of the attachment belt. However, the entire device is not easily removed (or re-installed) from the trailer, and is not readily portable once removed. Also, the entire device is not easily stored due to the bulk of the belt assembly, and because of the collection of crossing support battens and rods.
Other devices have similar drawbacks. As a result, few of these designs have been adopted to any significant extent. Thus, providing a vehicle air drag reduction apparatus or system which is easier to install or remove, or which provides improved access to the cargo space of a truck or trailer is still desired. As a result, it would still be advantageous to provide a vehicle air drag reduction apparatus that minimized or eliminated some or all of the disadvantages of the prior art devices.